public static bool? TryEvalAlternativeComparison(this ExpressionSyntax expression, ExpressionSyntax other, ISemanticModel model, Assumptions assume)
{
var val1 = expression.TryGetConstBoolValue();
var val2 = other.TryGetConstBoolValue();
if (val1.HasValue != val2.HasValue) return null;
if (val1.HasValue) return val1.Value == val2.Value;
if (expression is ParenthesizedExpressionSyntax) return ((ParenthesizedExpressionSyntax)expression).Expression.TryEvalAlternativeComparison(other, model, assume);
if (other is ParenthesizedExpressionSyntax) return expression.TryEvalAlternativeComparison(((ParenthesizedExpressionSyntax)other).Expression, model, assume);
if (expression.Kind == SyntaxKind.LogicalNotExpression) return !((PrefixUnaryExpressionSyntax)expression).Operand.TryEvalAlternativeComparison(other, model, assume);
if (other.Kind == SyntaxKind.LogicalNotExpression) return !expression.TryEvalAlternativeComparison(((PrefixUnaryExpressionSyntax)other).Operand, model, assume);
if (expression.HasSideEffects(model, assume) == false
&& expression.WithoutAnyTriviaOrInternalTrivia().ToString() == other.WithoutAnyTriviaOrInternalTrivia().ToString())
return true;
return null;
}
